U.S. patent application number 15/088947 was filed with the patent office on 2016-10-06 for catalyst composition and process for obtaining a colored olefin polymer.
This patent application is currently assigned to Reliance Industries Limited. The applicant listed for this patent is Reliance Industries Limited. Invention is credited to Mahuya Bagui, Satya Srinivasa Rao Gandham, Raksh Vir Jasra, Ajit Behari Mathur, ViralKumar Patel, Yogesh Popatrao Patil, Uma Sankar Satpathy, Krishna Renganath Sharma.
Application Number | 20160289422 15/088947 |
Document ID | / |
Family ID | 57016961 |
Filed Date | 2016-10-06 |
United States Patent
Application |
20160289422 |
Kind Code |
A1 |
Bagui; Mahuya ; et
al. |
October 6, 2016 |
CATALYST COMPOSITION AND PROCESS FOR OBTAINING A COLORED OLEFIN
POLYMER
Abstract
A catalyst composition and a process for obtaining a colored
olefin polymer are disclosed. The composition comprises a
Ziegler-Natta catalyst and an additive component comprising a
colorant. The catalyst composition enables a directly colored
polymer to be prepared. The colored polymer has a homogeneous
dispersion of the colorant in it and thus has no color defects.
Inventors: |
Bagui; Mahuya; (Vadodara,
IN) ; Patil; Yogesh Popatrao; (Mumbai, IN) ;
Patel; ViralKumar; (Nadiad, IN) ; Sharma; Krishna
Renganath; (Kerala, IN) ; Jasra; Raksh Vir;
(Vadodara, IN) ; Mathur; Ajit Behari; (Vadodara,
IN) ; Satpathy; Uma Sankar; (Vadodara, IN) ;
Gandham; Satya Srinivasa Rao; (Tadepalligudem, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Reliance Industries Limited |
Mumbai |
|
IN |
|
|
Assignee: |
Reliance Industries Limited
Mumbai
IN
|
Family ID: |
57016961 |
Appl. No.: |
15/088947 |
Filed: |
April 1, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 110/02 20130101;
C08F 2500/18 20130101; C08L 23/06 20130101; C08F 4/6425 20130101;
C08L 23/06 20130101; C08K 5/0091 20130101; C08F 110/02 20130101;
C08F 2410/01 20130101; C08K 5/0091 20130101; C08K 5/3417 20130101;
C08F 110/02 20130101; C08K 5/3417 20130101 |
International
Class: |
C08K 5/3417 20060101
C08K005/3417; C08F 110/02 20060101 C08F110/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 1, 2015 |
IN |
1394/MUM/2015 |
Claims
1. A catalyst composition for obtaining a colored olefin polymer,
said composition comprising: a) a Ziegler-Natta catalyst, wherein
said Ziegler-Natta catalyst comprises a pro-catalyst component and
a co-catalyst component; and b) an additive component, wherein said
additive component comprises a colorant.
2. A catalyst composition for obtaining a colored olefin polymer,
said composition comprising: c) a Ziegler-Natta catalyst, wherein
said Ziegler-Natta catalyst comprises a pro-catalyst component and
a co-catalyst component; and d) an additive component, wherein said
additive component comprises a colorant, wherein said additive
component is present in an amount in the range of 0.005 wt % to 0.5
wt % of the amount of said olefin polymer to be formed and said
colorant in said additive component is present in an amount in the
range of 0.005 wt % to 0.5 wt % of the amount of said olefin
polymer to be formed.
3. The composition as claimed in claim 2, wherein said colorant is
a Lewis base compound.
4. The composition as claimed in claim 2, wherein said colorant is
at least one selected from the group consisting of phthalocyanine
blue, phthalocyanine green, methyl violet, iso-indoline,
perylene-3,4,9,10-tetracarboxylic di-anhydride, Bismarck Brown Y,
and azo compounds and mixtures thereof.
5. The composition as claimed in claim 2, wherein the molar ratio
of said pro-catalyst to said co-catalyst is in the range of 1:10 to
1:18.
6. A process for preparing a colored olefin polymer, said process
comprising the following steps: (a) adding a Ziegler-Natta catalyst
comprising a pro-catalyst component and a co-catalyst component to
a first organic medium in a reactor to obtain a catalyst mixture;
(b) separately preparing an additive component mixture by
sonicating a mixture comprising an additive component comprising a
colorant, and a second organic medium, in an ultrasonic bath for a
time period in the range of 5 min to 30 min and introducing said
additive component mixture to the catalyst mixture to obtain a
catalyst-additive component mixture, wherein said additive
component is taken in an amount in the range of 0.005 wt % to 0.5
wt % of the amount of said olefin polymer to be formed and said
colorant is taken in an amount in the range of 0.005 wt % to 0.5 wt
% of the amount of said olefin polymer to be formed; and (c)
introducing at least one olefinic monomer into said
catalyst-additive component mixture in said reactor and carrying
out polymerization of said olefinic monomer to obtain a colored
olefin polymer.
7. The process as claimed in claim 6, wherein the polymerization,
is carried out at a temperature in the range of 50.degree. C. to
80.degree. C., a pressure in the range of 0.5 bar to 8 bar and for
a time period in the range of 1 hr to 3 hr.
8. The process as claimed in claim 6, wherein said colorant is at
least one selected from the group consisting of phthalocyanine
blue, phthalocyanine green, methyl violet, iso-indoline,
perylene-3,4,9,10-tetracarboxylic di-anhydride, Bismarck Brown Y,
and azo compounds and mixtures thereof.
9. The process as claimed in claim 6, wherein the molar ratio of
said pro-catalyst to said co-catalyst component is in the range of
1:10 to 1:18.
10. The process as claimed in claim 6, wherein the olefinic monomer
is selected from C.sub.2-C.sub.20 alpha-olefins.
11. The process as claimed in claim 6, wherein the first organic
medium is at least one selected from the group consisting of
paraffins.
12. The process as claimed in claim 6, wherein the second organic
medium is at least one selected from the group consisting of
paraffins.
13. A colored olefin polymer obtained by the process as claimed in
claim 6.
Description
FIELD
[0001] The present disclosure relates to polymers.
DEFINITIONS
[0002] Lewis base: A Lewis base is any species that donates an
electron pair to an electron acceptor.
[0003] Sonication: Sonication is the process of application of
sound energy, especially, ultrasound, to agitate components of a
given sample.
BACKGROUND
[0004] The polymerization of olefinic monomers can be carried out
using Ziegler-Natta catalyst systems. They can also be prepared
using metallocene type catalyst compositions. Conventionally, such
polymers are compounded with additives by dry blending the
polymeric material in the form of pellets or powder with the
additives and then melt blending them to form a well dispersed
compounded olefin polymer.
[0005] Colorants that add aesthetic appeal to polymeric material,
are also compounded first by dry blending and then by melt blending
with the polyolefinic material. Another method to color olefin
polymers is to melt blend them with colored master batches. Some
polymers such as UHMWPE are difficult to melt blend and hence they
have a limitation in adding colorants in their matrix. Also, the
conventional method of coloring may result in non-uniform
dispersion of the colorant.
[0006] Several entities, today, have their trademarks displayed on
their advertisement billboards and product packaging. By rule, the
color used in trademarks must not deviate. If the plastics used to
prepare the packaging material exhibit even a slightly different
color, the batch will be rejected. The conventional methods for
coloring plastics do not always result in the same color and hence,
cause a lot of wastage.
[0007] Hence, there is a felt need to provide for a method for
coloring of olefin polymers that will result in homogeneous
dispersion of the colorant in the polymer, at the same time, the
plastics retain their properties in their colored form. The method
of coloring should not cause any adverse effects on the polymers
and should exhibit substantially the same color shade batch after
batch.
OBJECTS
[0008] Some of the objects of the present disclosure, which at
least one embodiment herein satisfies, are as follows.
[0009] It is an object of the present disclosure to ameliorate one
or more problems of the prior art or to at least provide a useful
alternative.
[0010] An object of the present disclosure is to achieve olefin
polymers that have homogeneous dispersion of colorants in them.
[0011] Another object of the present disclosure is to achieve
olefin polymers that do not have any color defects.
[0012] Still another object of the present disclosure is to achieve
colored olefin polymers that retain the properties of the uncolored
olefin polymers.
[0013] Yet another object of the present disclosure is to achieve
substantially the same color shade batch after batch.
[0014] Other objects and advantages of the present disclosure will
be more apparent from the following description, which is not
intended to limit the scope of the present disclosure.
SUMMARY
[0015] A catalyst composition for obtaining a colored olefin
polymer is disclosed. The catalyst composition comprises a
Ziegler-Natta catalyst and an additive component. The additive
component comprises a colorant. Typically, the additive component
is taken in an amount in the range of 0.005 wt % to 0.5 wt % of the
amount of olefin polymer to be formed. Typically, the colorant in
the additive component is present in an amount in the range of
0.005 wt % to 0.5 wt % of the amount of the olefin polymer to be
formed.
[0016] The Ziegler-Natta catalyst comprises a pro-catalyst
component and a co-catalyst component. Typically, the pro-catalyst
component comprises at least one transition metal compound and
optionally, a magnesium compound. Typically, the co-catalyst
component comprises at least one organoaluminium compound.
[0017] Typically, the colorant in the additive component is a Lewis
base compound. Typically, the colorant is at least one selected
from the group consisting of phthalocyanine blue, phthalocyanine
green, methyl violet, iso-indoline,
perylene-3,4,9,10-tetracarboxylic di-anhydride, Bismarck Brown Y,
and azo compounds and mixtures thereof.
[0018] In another aspect of the present disclosure, a process for
preparing a colored olefin polymer is provided herein.
[0019] A Ziegler-Natta catalyst comprising a pro-catalyst component
and a co-catalyst component is mixed with a first organic medium in
a reactor, while stirring, to obtain a catalyst mixture.
Separately, a mixture comprising an additive component comprising a
colorant, and a second organic medium is sonicated in an ultrasonic
bath to result in an additive component mixture. Typically, the
additive component is present in an amount in the range of 0.005 wt
% to 0.5 wt % of the amount of the olefin polymer to be formed.
Typically, the colorant in the additive component is present in an
amount in the range of 0.005 wt % to 0.5 wt % of the amount of the
olefin polymer to be formed.
[0020] The additive component mixture is then added to the reactor
containing the catalyst mixture while stirring to obtain a
catalyst-additive component mixture. At least one olefinic monomer
is then introduced into the catalyst-additive component mixture in
the reactor while stirring and allowed to polymerize.
[0021] Typically, the polymerization is carried out at a
temperature in the range of 50.degree. C. to 80.degree. C., a
pressure in the range of 0.5 bar to 8 bar and for a time period in
the range of 1 hr to 3 hr. The polymerized product found is a
colored olefin polymer. Typically, the molar ratio of the
pro-catalyst to the co-catalyst is in the range of 1:10 to
1:18.
[0022] Typically, the olefinic monomer is selected from the group
consisting of C.sub.2-C.sub.20 alpha-olefins. Typically, the first
organic medium is at least one selected from the group consisting
of paraffins. Typically, the second organic medium is at least one
selected from the group consisting of paraffins.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
[0023] The present disclosure will now be described with the help
of the accompanying drawing, in which:
[0024] FIG. 1 illustrates a comparison between compression molded
sheets of a colored polyethylene prepared by a conventional method
and the colored polyethylene prepared using the catalyst
composition of the present disclosure.
DETAILED DESCRIPTION
[0025] The conventional methods of coloring of olefin polymers
result in some color defects in the polymers owing to non-uniform
dispersion of the colorant in the olefin polymer. This
non-uniformity in the dispersion of the colorant in the polymers
results in a lot of wastage as the batches which do not conform to
the desired color are rejected.
[0026] Polymers like UHMWPE are difficult to melt blend and hence
they have limitation in adding colors in their matrix. The present
disclosure, therefore, envisages preparing olefin polymers with
uniform dispersion of colorants in them and which retain their
properties.
[0027] In one aspect of the present disclosure, a catalyst
composition for directly obtaining a colored olefin polymer is
disclosed. The catalyst composition comprises a Ziegler-Natta
catalyst and an additive component. The additive component
comprises a colorant. The additive component is present in an
amount in the range of 0.005 wt % to 0.5 wt % of the amount of the
olefin polymer to be formed. The colorant in the additive component
is present in an amount in the range of 0.005 wt % to 0.5 wt % of
the amount of the olefin polymer to be formed. However, higher
loading of colorants in the polymer can be readily accomplished if
required. The additive component may, additionally, comprise
fillers, lubricants, plasticizers, and other additives.
[0028] The Ziegler-Natta catalyst comprises a pro-catalyst
component and a co-catalyst component. The pro-catalyst component
comprises at least one transition metal compound and optionally, a
magnesium compound. The transition metal compound is selected from
the group consisting of transition metal halides, transition metal
alkoxides, transition metal aryloxides, transition metal oxides and
transition metal halo oxides. In an embodiment of the present
disclosure, the transition metal compound is a titanium compound.
In a particular embodiment, the titanium compound is a titanium
halide.
[0029] The magnesium compound in the pro-catalyst component is
selected from the group consisting of magnesium halides, magnesium
alkoxides, magnesium aryloxides, magnesium oxyhalides, and
magnesium salts of inorganic acids.
[0030] The co-catalyst comprises at least one organoaluminium
compound. The organoaluminium compound is selected from the group
consisting of aluminium alkyls like triethyl aluminium (TEAL),
triisobutyl aluminium (TIBAL), triisoprenyl aluminium (TIPRA),
tri-n-octyl aluminium (TNOAL), and their homologues.
[0031] In accordance with the present disclosure, the molar ratio
of the pro-catalyst component and the co-catalyst component is in
the range of 1:10 to 1:18.
[0032] The colorant in the additive component is a Lewis base
compound. The colorant is at least one selected from the group
consisting of phthalocyanine blue, phthalocyanine green, methyl
violet, iso-indoline, perylene-3,4,9,10-tetracarboxylic
di-anhydride, Bismarck Brown Y, and azo compounds and mixtures
thereof.
[0033] According to another aspect of the present disclosure, a
process for preparing a colored olefin polymer is provided
herein.
[0034] A Ziegler-Natta catalyst comprising a pro-catalyst component
and a co-catalyst component is mixed with a first organic medium in
a reactor, while stirring at a rotational speed in the range of 5
rpm to 300 rpm, to obtain a catalyst mixture. Separately, a mixture
comprising an additive component comprising a colorant, and a
second organic medium is sonicated in an ultrasonic bath for a time
period in the range of 5 min to 30 min to result in an additive
component mixture. The additive component is taken in an amount in
the range of 0.005 wt % to 0.5 wt % of the amount of the olefin
polymer to be formed. The colorant in the additive component is
taken in an amount in the range of 0.005 wt % to 0.5 wt % of the
amount of the olefin polymer to be formed.
[0035] The additive component mixture is then added to the reactor
containing the catalyst mixture while stirring at a rotational
speed in the range 5 rpm to 300 rpm to obtain a catalyst-additive
component mixture. At least one olefinic monomer is then introduced
into the catalyst-additive component mixture in the reactor while
stirring at a rotational speed in the range of 5 rpm to 1500 rpm
and allowed to polymerize. The polymerization is carried out at a
temperature in the range of 50.degree. C. to 80.degree. C., a
pressure in the range of 0.5 bar to 8 bar and for a time period in
the range of 1 hr to 3 hr. The polymerized product formed is a
colored olefin polymer. The olefinic monomer is selected from the
group consisting of C.sub.2-C.sub.20 alpha-olefins. In a particular
embodiment, the alpha-olefin is ethylene.
[0036] In the process of the present disclosure, the molar ratio of
the pro-catalyst component and the co-catalyst component is in the
range of 1:10 to 1:18.
[0037] The first organic medium is at least one selected from the
group consisting of paraffins. In a particular embodiment, the
first organic medium comprises a mixture of C.sub.6 to C.sub.11
paraffins.
[0038] The second organic medium is at least one selected from the
group consisting of paraffins. In a particular embodiment, the
second organic medium is Varsol.TM. (a high boiling
C.sub.8-C.sub.11 paraffin mixture).
[0039] The obtained colored olefin polymer is further filtered,
washed, and dried to isolate the colored olefin polymer.
Non-limiting examples of the colored olefin polymer formed are
HDPE, UHMWPE, PP, and copolymers thereof.
[0040] The colorant of the present disclosure is a Lewis base
compound which has a tendency to donate electrons and interact with
the transition metal center of the Ziegler-Natta catalyst. It bonds
with the transition metal center of the Ziegler-Nana catalyst,
thus, stabilizing the oxidation state of the transition metal to
result in a modified Ziegler-Natta catalyst. During the
polymerization reaction, the polymer starts to grow around the
modified Ziegler-Natta catalyst metal center, enabling the uniform
dispersion of the colorant in the growing polymer chain, thus,
resulting in the formation of the colored polymer. The uniformity
of dispersion of color results in, substantially, the same color
shade batch after batch.
[0041] As the dispersion of the colorant is more uniform, the
amount of colorant required to achieve a given intensity of color
in the polymer product is lesser than that required by a
conventional mixing process. More so, for very high melt viscosity
polymers like UHMWPE, the dispersion of colorants by conventional
means is very difficult due to its flow limitations. The process of
the present disclosure is thus beneficial for coloring such high
melt viscosity olefin polymers. Also, by adding the colorants at
the polymerization stage, the mixing step is avoided which makes
the process of the present disclosure simple and cost
effective.
[0042] The present disclosure is further described in light of the
following laboratory experiments which are set forth for
illustration purpose only and not to be construed for limiting the
scope of the disclosure. The following experiments can be scaled up
to industrial/commercial scale and the results obtained can be
extrapolated to industrial scale.
EXPERIMENTS
Experiment 1
[0043] A 1 L Buchiglasuster Polyclave reactor with multiple inlets
and stirring means (a magnetic stirrer) was provided. The reactor
was made oxygen and moisture free before carrying out the
polymerization. It was connected to a cryogenic system to maintain
the desired temperature in the reactor. All operations were carried
out under nitrogen and moisture free atmosphere.
[0044] Approximately 500 mL of dry and pure Varsol.TM. (a high
boiling C.sub.8-C.sub.11 paraffin mixture) was charged into the
reactor. A 4.8 mL of co-catalyst solution was prepared separately
by adding 0.48 g of triethyl aluminium to 4.8 mL hexane.
Separately, 0.1159 g of pro-catalyst having the elemental
composition Mg:Ti:Cl=1:1.3:3.7 is dissolved in 1 mL of hexane to
obtain a pro-catalyst solution. 4.8 mL of the co-catalyst solution
and 0.27 mL of the procatalyst solution were added to reactor under
gentle nitrogen flow. The amounts of pro-catalyst and the
co-catalyst resulted in an Al/Ti molar ratio of 14 for
polymerization. In a separate vessel, a colorant mixture containing
10 mg of phthalocyanine blue colorant (colorant) and 25 mL of dry
Varsol.TM. was taken. The colorant mixture was sonicated in an
ultrasonic bath at room temperature (30.degree. C.) for 10 min. The
sonicated colorant mixture was then charged into the reactor to
obtain a catalyst-colorant mixture. The reaction mixture was then
bubbled with a gentle flow of ethylene gas to remove all entrapped
nitrogen gas from the system. The reactor was then closed and
pressurized with ethylene to 2.5 bar to initiate polymerization.
Polymerization was continued at 75.degree. C. for 2 hr. After 2 hr,
when no further consumption of ethylene was observed, the reaction
was stopped and its temperature was reduced to room temperature.
Excess ethylene was carefully and slowly removed from the reactor
and collected. The slurry from the reactor was filtered to obtain a
blue colored polyethylene powder which was dried in an oven at
70.degree. C. under vacuum for a couple of hours. The quantity of
blue colored polyethylene obtained was 200 g. It was found that the
polyethylene obtained was colored blue uniformly.
Experiment 2
Comparative Experiment
[0045] Polymerization was carried out in a similar manner as
Experiment 1 except without adding any phthalocyanine blue colorant
mixture. 215 g of white colored polyethylene powder was
obtained.
TABLE-US-00001 TABLE 1 A comparison of colored polyethylene of
Experiment 1 and the polyethylene of Experiment 2 Reduced Specific
Bulk Polyethylene Viscosity Density Colorant obtained (RSV) dL/g
g/cc Remarks Phthalocyanine 200 20.6 0.42 A uniform blue blue
powder No colorant 215 18.7 0.46 A uniform white powder
[0046] Table 1 shows a comparison between the blue colored
polyethylene obtained from Experiment 1 and the white polyethylene
obtained from Experiment 2. The polyethylene obtained from
Experiment 1 was uniformly colored polyethylene powder.
Experiment 3
Comparative Experiment
[0047] 10 mg of phthalocyanine blue colorant was dissolved in 10 ml
of Varsol.TM.. This solution was mixed with 20 g of white colored
polyethylene powder obtained in Experiment 2 to obtain the
polymer-colorant mixture. The polymer-colorant mixture was mixed
well for 20 min and then kept for drying at 70.degree. C. for 3 hr
under vacuum to obtain a dried colored polymer powder. The dried
colored polymer powder was compression molded into a 0.5 mm thin
sheet at 170.degree. C. and 200 bar pressure.
[0048] The blue colored polyethylene obtained from Experiment 1 was
also compression molded under identical conditions to obtain a 0.5
mm thin sheet. Both the sheets were compared for color dispersion.
It was observed that the sheet made from the blue colored
polyethylene obtained from Experiment 1 had far better dispersion
of colorant than the sheet made conventionally.
[0049] FIG. 1 illustrates the comparison between compression molded
sheets of a colored polyethylene prepared by a conventional method
(A) and the colored polyethylene prepared using the catalyst
composition of the present disclosure (B).
[0050] It is seen that the sheet of colored polyethylene prepared
by the conventional method is lighter than the sheet of colored
polyethylene prepared by the process of the present disclosure.
Experiment 4
[0051] Many batch polymerization reactions were carried out similar
to Experiment 1. The blue colored polyethylene powder obtained from
five batches were compression molded into sheets of 0.5 mm
thickness and were checked for L*, a*, and b* values. The L*, a*,
and b* values of the five batches were substantially the same
indicating that every batch resulted in the same color shade. This
exhibits the color consistency of the colored polyethylene from
batch to batch.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
[0052] The present disclosure described herein above has several
technical advantages including, but not limited to, the realization
of colored olefin polymers that: [0053] have a homogeneous
dispersion of colorants in them; [0054] do not have any color
defects; [0055] retain the properties of the uncolored olefin
polymers; and [0056] exhibit the same color shade batch after
batch.
[0057] The foregoing description of the specific embodiments so
fully reveals the general nature of the embodiments herein that
others can, by applying current knowledge, readily modify and/or
adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such
adaptations and modifications should and are intended to be
comprehended within the meaning and range of equivalents of the
disclosed embodiments. It is to be understood that the phraseology
or terminology employed herein is for the purpose of description
and not of limitation. Therefore, while the embodiments herein have
been described in terms of preferred embodiments, those skilled in
the art will recognize that the embodiments herein can be practiced
with modification within the spirit and scope of the embodiments as
described herein.
[0058] Throughout this specification the word "comprise", or
variations such as "comprises" or "comprising", will be understood
to imply the inclusion of a stated element, integer or step, or
group of elements, integers or steps, but not the exclusion of any
other element, integer or step, or group of elements, integers or
steps.
[0059] The use of the expression "at least" or "at least one"
suggests the use of one or more elements or ingredients or
quantities, as the use may be in the embodiment of the disclosure
to achieve one or more of the desired objects or results.
[0060] Any discussion of documents, acts, materials, devices,
articles or the like that has been included in this specification
is solely for the purpose of providing a context for the
disclosure. It is not to be taken as an admission that any or all
of these matters form a part of the prior art base or were common
general knowledge in the field relevant to the disclosure as it
existed anywhere before the priority date of this application.
[0061] The numerical values mentioned for the various physical
parameters, dimensions or quantities are only approximations and it
is envisaged that the values higher/lower than the numerical values
assigned to the parameters, dimensions or quantities fall within
the scope of the disclosure, unless there is a statement in the
specification specific to the contrary.
[0062] While considerable emphasis has been placed herein on the
components and component parts of the preferred embodiments, it
will be appreciated that many embodiments can be made and that many
changes can be made in the preferred embodiments without departing
from the principles of the disclosure. These and other changes in
the preferred embodiment as well as other embodiments of the
disclosure will be apparent to those skilled in the art from the
disclosure herein, whereby it is to be distinctly understood that
the foregoing descriptive matter is to be interpreted merely as
illustrative of the disclosure and not as a limitation.
* * * * *